Characterization of CdTe detector for use in PET

CdTe diode detectors with Schottky contact have been characterized in terms of energy resolution and time of response. A resolution of 0.98% at 511keV has been achieved with a 4 mm × 4 mm × 2 mm detector at 900 V/mm and -7 °C. At the same bias and temperature conditions, two identical CdTe detectors show a coincidence time FWHM of 25 ns. Additionally, the effect of a strong magnetic field on the charge sharing has been studied for a 9-pixel array detector of 55 μm × 55 μm × 800 μm pixel size connected to MediPix2 front end electronics. No effect on the charge sharing distribution has been observed up to 4 T. These results show that CdTe Schottky diodes are excellent candidates for the development of next generation nuclear medical imaging devices such as PET, Compton gamma camera, and especially PET-MRI when used in a magnetic field immune configuration.